The aforementioned application describes a process whereby arsenic, antimony and bismuth, present as impurities in electrolytes, can be removed in a simple manner by chemisorption without multistage treatment of the electrolyte so that the latter can be recirculated to non-ferrous-metal refining baths and super saturation of the impurities in the electrolyte is prevented.
This process makes use of a floating chemisorption agent in that the chemisorbent is applied to a floating substrate. The process involves chemisorption to remove the impurities from the electrolyte, followed by regeneration of the chemisorbent by treating it with regenerating agent.
The cycling of the chemisorption agent in this manner results in degradation of the chemisorption agent with the formation of fine-grain detritus which plugs the inlet, outlet or passages of the treating vessel and reduces the throughflow of the electrolyte. This disadvantage is all the more significant since the low solubility of the impurities makes it necessary to bring large quantities of liquid into contact with the chemisorption agent.
The floating chemisorbent, moreover, is not always able to be brought into the desired degree of intimate contact with the electrolyte.